The present invention relates, in general, to apparatus for producing flow modulation epitaxy, and more particularly relates to a high throughput organometallic vapor phase epitaxy (OMVPE) apparatus for deposition of material on substrates. In a preferred embodiment, the invention is directed to a cold wall reactor which is convertible to a hot wall, reactor for epitaxial deposition of compound semiconductor materials.
Reactors for use in chemical vapor deposition, for example for epitaxial processing of semiconductor materials, or wafers, are generally well known. Two types of reactor are available for epitaxial processing, one being referred to as a cold wall reactor and the other being referred to as a hot wall reactor. Both types are well known, and the particular reactor used depends upon the type of reaction to be performed. For example, silicon processing is normally done in a hot wall reactor device.
In a chemical vapor deposition reactor, the chemicals used in the process have a tendency to decompose on the cell wall, as well as on the substrate as they flow through the cell. Layers of decomposed reactants build on the cell wall and eventually these layers begin to flake off, producing particulate contaminates in the cell which damage the wafer being processed. In addition, certain compounds produce a chemical memory effect; i.e., impurities accumulate on the cell wall, and then are released during a later run, contaminating that later run. To prevent such contamination, the cells must be periodically cleaned.